1. Field of the Invention
The present invention relates to circuit modules and methods of managing circuit modules, and more particularly, to circuit modules that include identification codes and methods of managing circuit modules.
2. Description of the Related Art
Methods of manufacturing various types of circuit modules include a method of forming a plurality of circuit modules at the same time as a mother substrate and dividing the mother substrate into individual circuit modules in a final stage.
Japanese Unexamined Patent Application Publication No. 2007-42934 discloses a method of managing the manufacturing histories of such circuit modules and mother substrates.
Referring to FIG. 1, a method of managing the manufacturing histories of multiple substrates and the multiple substrates disclosed in Japanese Unexamined Patent Application Publication No. 2007-42934 is described.
A multiple substrate 10 illustrated in FIG. 1 is a substrate including, for example, four divided substrates 11 to 14, arranged in a matrix, to be separated into four substrates after components are mounted thereon. A substrate identification code (substrate ID) 20 is provided in a portion other than the divided substrates, and circuit identification codes (circuit IDs) 22 are provided on the divided substrates 11 to 14.
The substrate identification code 20 is unique so as not to be the same as that of another multiple substrate 10, and each of the circuit identification codes 22 includes the substrate identification code 20 as a portion thereof.
For example, when the substrate identification code 20 is [00010], the circuit identification codes 22 of the division substrates 11 to 14 may be [00010-001], [00010-002], [00010-003], and [00010-004].
However, when identification codes are to be provided, there has been a problem in that spaces for providing the identification codes are required, resulting in individual division substrates having increased sizes. Specifically, since many electrodes are formed on the back surfaces of the substrates, there has been a problem in that new spaces for providing the identification codes are required.
In addition, in the case where packaging using resin sealing is used instead of conventional metal caps to make circuit modules thinner, if identification codes are provided inside the resin seal, it is difficult to read the identification codes at the time of defect analysis.
Further, in the case of sealing with a resin, separation at the interface between a substrate and a sealing resin, for example, is a big problem in view of reliability. Hence, traceability that enables monitoring of occurrences of defects is required.